Of Knights and Titans
by Ania the Dragon
Summary: The world is overrun by man-eating monsters… The walls cannot protect the people for much longer… The soldiers are growing weary and tired… All hope seems lost... And Arthur just wonders whether it's Merlin's fault or not.
1. Chapter 1

A/N **: I own nothing!**

 _I'm sorry, but this plot bunny's been bothering me for some time now and I just had to write it. No prior knowledge of the Fate universe is required but I based the characters on how they're portraied in the series, so there's that. This is an one-shot for now, but if'd like me to continue this, let me know.  
Also, I'm not native English speaker and I don't have a beta, so there are probably some grammar mistakes.  
(The bunny should be satisfied now so I can hopefully get back to Always expect the unexpected…)_

I.

Arthur isn't sure what to think about his current situation aside from the sheer wrongness of it. He looks around, taking note of the blue sky and huge, bone-white wall. The wall bothers him. A lot. Which is weird, because Camelot's walls have never made him feel so… trapped. Indeed, there is no feeling of security with this particular wall, just the entrapment. Arthur frowns, looking at his hands. His small hands. Child's hands.

He stands up and begins to walk home, still pondering about the bizarre situation he found himself in. He doesn't know that much about the phenomenon of reincarnation, but he is pretty sure this is not how it is supposed to work. So Arthur, otherwise known as Eren Yeager, does the only logical thing he can – he blames Merlin.

II.

The first one of his knights he finds is Galahad. It takes him by surprise – he supposed that he is alone in this strange place. The surprise is even more pleasant, because Galahad recognizes him. The whole incident happens somewhat like this:

He is walking down the street, once again lost in thoughts. However, his musings are rudely interrupted by the sounds of a struggle echoing from nearby backstreet. He goes after the sounds only to find two boys, a little older than the current him, kicking and ridiculing a smaller boy – girl? Arthur Eren isn't sure but it matters little – he is having none of this. Bullying is wrong, in whichever form it appears.  
He promptly takes care of the two rude boys (there are no real match for him, just clumsy children and even though his body is tiny, he still has a lot more experience in fighting than they do) and pats the small, blonde boy on the head.

"Shh, It's okay now, they won't hurt you anymore."

Two sky blue eyes stare into his own emerald green.

"I- thank you, um-" The blue yes suddenly widen, "My- my lord!?"

Arthur Eren jerks his hand away, baffled. Then he looks again, properly this time.

"Galahad?"

The blonde child nods eagerly, "My lord Arthur!"

"It's actually Eren now, Galahad. It's very nice to see you again."

"I go by Armin Arlert, my lord. Do you have any idea what is going on?"

"No, not really. I became aware of myself just recently. That being said, I blame Merlin."

"Ah, understandable."

III.

The next one is Lancelot, and it certainly is a meeting to remember. If only because Lancelot is a girl this time around. Doesn't stop him from being a formidable opponent, however.

He has to thank his "father" for the opportunity, however unintentional it is. If one Grisha Yeager weren't a doctor and a friend of Lancelot's parents… He doesn't want to think about that could possibly have happened.

But it is as it is, and he barges into the house just in time to save his strongest knight. And then Lancelot immediately returns the favour, by killing the one bandit that manages to sneak undetected upon Arthur.

Arthur (Eren, it is Eren now) have wondered whether his knights remember by their own, or if a physical contact with him is necessary. Lancelot confirmed that it is the latter, because the girl he now is shows no recognition of him until he places his hand onto her shoulder, trying to comfort her after her (presumably) first kill. The moment he touches her she looks him in the eye, then drops on one knee and whilst lowering her head, whispers apologies.

"I'm not asking for forgiveness, my liege – whatever punishment you see fit for me, I shall accept. Just know, please, that my regrets follow me still and even though I can't reverse my actions-"

"Stop apologizing already, and look at me, Lancelot du Lac."

This makes him (her? Them?) stop and turn his (her? Their?) attention back to Arthur Eren.

"I forgive you. After all, we had an eternity to ponder about our mistakes, my friend. You have suffered enough already."

"My liege-"

"Shush. This is a chance to start over – let us not repeat the mistakes of our past. I would like to have you by my side once more."

Arthur Eren smiles, green eyes a little watery. He holds out his hand.

"I'm called Eren, in this new life. How shall I address you?"

Lancelot stands up, taking the offered hand.

"My name now is Mikasa Ackerman. But you can address me however you see fit, my liege."

"Mikasa it is, then."

It is at this moment, that one Grisha Yeager arrives, the police in tow. He starts fussing, of course, about the blood and the corpses, but Arthur Eren is just trying to think about a good way to reintroduce Lancelot to Galahad…

IV.

Galahad and Lancelot are indeed an explosive combination, but not as much as Arthur Eren feared. Since there are no blood ties between the two this time around, they seem to accept each other existence more easily. They both also agree that Arthur Eren needs to be protected at all cost, which is sometimes really annoying. He is not going to object, though. After all, hell hath no fury like a woman scorned. He isn't sure how "womanly" Lancelot feels, but… Better not push his luck. He isn't the luckiest person around, for sure.

V.

Arthur Eren still doesn't have any firm grasp of their situation. Of course, reincarnation is the most logical conclusion, seeing as they are different people now, but it still makes no sense. He is fairly certain they've all ended becoming Heroic spirits and to just disappear from the Throne of Heroes… Is the world in danger? If so, why weren't they just summoned, instead of reincarnating into human, mortal bodies? And if they aren't humans, then what?

He gets some answers to his question when he isn't expecting it all. Nothing new here.

He once again has to thank one Grisha Yeager for them.

Arthur Eren knows that there is something _wrong_ with his "father" – it's obvious – but he gets the feeling it's getting worse. His worries turn out to be justified when Grisha tries to inject a weird substance into his body. There is a crazed look in his "father's" eyes and his fingers are trembling, but he still holds Arthur Eren firmly.

(So firmly, in fact, that it leaves deep purple bruises on his arm. When Lancelot discovers then, he looks ready to murder one Girsha Yeager. Galahad is no better, he offers to hide the body.)

Nothing happens, at first. Then there is an agonizing pain and all of sudden he's holding Excalibur in his hand. Whatever his "father" expected to happen, this was not it. Arthur Eren is equally surprised. Because this is the real deal, the real Sword of Promised Victory, no mere illusion. A Noble Phantasm. Puzzled, he touches the edge – it's warm. Grisha Yeager bolts. Arthur Eren doesn't see him for a long time.

Then the Wall is breached and everything goes straight to Hell.

VI.

He doesn't even have time to properly mourn the death of his mother and suddenly there are people yelling at him. Or shouting orders. Or both.

He takes it better than Lancelot. And Galahad. Neither of them likes to be yelled at. Arthur Eren has to physically restrain them. Killing your teachers doesn't usually help you graduate, after all. Not that his knights, when in overprotective mode, care. Ah, joy.

VII.

In a short sequence, he meets several of his knights. They all happen to be in the same squad of trainees, and isn't it such a great coincidence? This just has 'Merlin' written all over it, Artur knows it. He kind of wishes that the magician was there, so he could either strangle him of hug him. It would depend.

Back to the knights, though. Tristan is a girl in this new life, which is somehow really funny. Arthur Eren isn't exactly sure why he founds it so hilarious, maybe because Tristan is still chasing after cute blondies. He clearly hasn't learnt a thing from his tragic end by the hands of another blonde lady. His name now is Ymir and Arthur Eren bums into him unintentionally when the former redhead is trying to find Krista, the cute blonde girl that reminds Arthur of a rabbit.

"Outta my way, idiot!" He She yells and tries to push Arthur away. Keyword here is "tries" – the moment he She touches Arthur Eren He She flinches as if burnt. He she is clutching his her hand and appears to be quite shaken when he she looks at Arthur Eren properly. Then His Her eyes widen and Arthur Eren can't help it but smile.

"Still chasing after blondes, are we?" He smiles wryly.

"M- my lord!" He She squeaks, confused. "What-?"

"Not here, not now, Tristan." Arthur stops his her questions with a raised hand, "We'll met later in secret, and I'll tell you the little I know."

Tristan nods and bows a little. It's better than Lancelot who still tends to kneel which is not subtle at all, especially when they're trying not to attract any unwanted attention.

"Wait, before you go, may I inquire your new name, friend?"

Tristan halts, turns back to Arthur Eren and smiles: "I'm Ymir. You?"

"Eren."

VIII.

Arthur's meeting with Bedivere fortunately occurs without any incidents, and isn't Arthur grateful for that. Bedivere is also a girl now, which – if Arthur's being honest – isn't that much of a change (Bedivere was rather girly even then). He She's also amazingly passive-aggressive in such a way it brings smile to Arthur's Eren's face (even though it probably shouldn't). The whole "Why-people-eat-potatoes" fiasco was truly a sight to behold. It even helped Arthur Eren learn Bedivere's new name, Sasha.

They meet properly a few days after the „event" and once Bedivere Sasha recognizes Arthur, he she proceeds to hug him to death. It almost ends badly though, because Lancelot feels like this is way too much physical contact for Arthur. The aftermath of this is a bit awkward and the two knights avoid each other for a few days, but all's well that ends well, right?

IX.

If Arthur though that meeting Lancelot was an interesting one, he later discovers that he was wrong. Nothing tops meeting Gawain again. If only because it takes so long for the knight to recognize him. (Funnily enough, even if they spar, they somehow avoid actually touching for more than a few seconds and Gawains past memories never surface.)

This leads to a situation in which Gawain sort of hates Arthur Eren and said king has to spend a lot of effort in keeping the rest of the knights away from Gawain. Who is now called Jean. The name doesn't really suit him all that much, but who is Arthur Eren to judge?

Gawain's 180° personality flip, when he finally remembers, is absolutely hilarious.

X.

Now, when they are all standing in the ruins of Trost, weapons in hand, Arthur still isn't sure what to think. Of this world, of the people in it, of the bizarre situation he found himself in. But he also figures that, ultimately, it doesn't matter. He looks at his knights and even if the faces are different, the souls and hearts aren't.

And that's the only important thing, really. With his friends by his side, he can take whatever the world decides to throw at him.

This is also called tempting the fate and it will come and bite Arthur later, that's for sure.

For now though… The times are as peaceful as they can be when there are giant man-eating monsters attacking you.

And monsters, the Knights of the Round Table can handle.


	2. Chapter 2

**Disclaimer: I own nothing!**

 _Wow, I was not anticipating such a positive response! Thank you so much! It completely caught me off guard and I had to sit down and think hard about the direction I want to take with this story. And there are two possibilities: 1) I can either turn this whole thing into a Lostbelt, in which case you need to know some Fate lore to for this to make sense, or 2) I can just go with the "King under the mountain" part of the Arthurian legends. So what do you think? Let me know!_

 _I apologize that this chapter is so descriptive, I wanted to finish Trost as fast as possible. It was originally supposed be just a smaller part of a bigger chapter, but I decided to instead do this, so I can fully focus on the relationship between the knights in the next chapter. After all, what better place to explore their personalities that a trial? *evil grin*_

 _Also, to answer your questions:_

*Yes, I am using proto-Arthur. Yes, I am aware that according to the version of him we have in Grand Order, his Merlin is female. But I am working with the male version of Merlin, simply because I like his design and it corresponds with the legend a bit better. Though honestly, Merlin's gender is kind of irrelevant, he would still be a troll and a flirt even as a girl.

*No, Merlin is no Hanji, though that idea was tempting for a long while. Merlin's still alive, just sealed away.

*Ymir is not titan in this and is on Eren's side. The other shifters most will most likely remain Titans.

*And before anyone asks about Mordred – I don't plan to include her, unless this story takes an unexpected turn to the dark side (which it shouldn't this is pretty much a crack). Let the poor thing rest in peace.

 **Just a quick note: The formating of removed all my crossed words, I replaced them with /../. Hopefully it won't be too confusing.**

I.

This situation, Arthur supposes, could be a lot worse. It could also be a lot better, he musses as he looks down onto the chaos below him. It reminds him of Shingashina, five years ago, and that's not a comforting thought. Everything happened almost the same way – a titan, bigger than what is thought possible, a hole in the wall and then just chaos and death.

/Arthur/ Eren grips the handle of his weapon. It's no Excalibur, but it'll have to do. (There's no point in showing his trump card just yet, when he still has no idea what exactly is going on). He slowly exhales and exchanges a look with /Lancelot/ Mikasa. She nods briskly, knowing exactly what he wants her to do. After all, she is physically stronger than him (no matter how much admitting that wounds his pride… Well, it doesn't, not really. His friend was always stronger than him, physically speaking) so she will be the muscle of the group. The other knights will have to adjust accordingly, taking into consideration limitation of their human bodies.

With this in mind, he jumps into the fray, following Mikasa, with his knight in tow.

II.

The worst thing about this is, that nobody listens to him. Arthur has some experience fighting giants, from his days as a king, even though back then the danger was more of being trampled over than being eaten alive. Arthur's not sure what's better.

Not that it matters, because people would apparently rather panic and run around like a bunch of headless chicken than listen to a kid. Who is apparently the only one calm about this situation. Well, okay, to be fair, not everybody is panicking, but most of the people are. Including the military personnel. Which is supposed to be trained for these kinds of situation. For Merlin's sake, this world is a mess.

III.

Arthur, of course, doesn't let other people incompetence hinder his efforts. He'd be damned if he doesn't try to save as many people as he can. And his knights are quite good at this whole killing giant monster things. A bit too good, even. He probably should be worried. Arthur decides he doesn't really care.

At least until he gets swallowed by a rather ugly giant (even though they are all hideous) and is forced to unleash his Noble Phantasm. That was not accounted for. At all.

It happens, because he tries to save /Galahad/ Armin, who has run out of gas and is desperately trying to fend the giants off with one of the knives (Arthur is reluctant to call these weapons swords). But trying to keep these towering monsters at bay whilst balancing on a roof with said monsters slowly circling around is a fool's errand. At one point, Armin slips and is falling, falling towards his death.

Arthur doesn't think, and just lunges forward.

"Armin!" he yells, not caring that the monsters around can hear, and catches Armin's hand, pulling him back onto the roof.

"Eren, what are you doing!?" Armin tries to say, but he is having trouble catching his breath, so the words come out a little slurred. He is still holding /Arthur/ Eren's hand, trying to steady himself.

"Saving you from a certain death, perhaps?" /Arthur/ Eren teases his friend, but suddenly he is shoving Armin away, hard, because the nearest titan decided they shall be its dinner. Lunch. Meal. Whatever.

"Wha-" Armin squeaks and almost loses his footing again but manages to stay on the roof. Eren is not so lucky, his feet slip on the roof tiles and he slides down and off the roof.

One of the titans, a rather hideous one, snatches him and proceeds to swallow him whole. He tries to fight, but the beast has a firm grip, and he is only human, his strength nothing compared to that of those fiends. The last thing /Arthur/ Eren hears is Armin's horrified yell of "My lord, no-!"

Then the titan closes its mouth and /Arthur/ Eren knows he's screwed.

IV.

Being eaten alive is not a pleasant sensation, Eren wouldn't wish it even onto his worst enemies. Titan's insides are slimey, gross and acidic. There's no way he'd be able to climb back or even stop his fall somehow. Absently, Eren notes that these creatures have really easy digestive system.

He weights his options, as he falls towards his death. Only, he doesn't really have a choice, does he, if he wishes to live. He feels like such a hypocrite, because he forbade his knights the very things he's about to do. But, this counts as an emergency, right? Either way, time's up. Eren doesn't wish to test just how corrosive are the acids in the titan's belly. He summons his trusty blade, The Sword of Promised Victory, and prays that everything goes all right. It does. Kind of.

V.

/Galahad/ Armin is horrified when one of the beasts swallow his beloved king and friend. More so because he knows he's at fault here – if he had been a bit more careful with his gas, he wouldn't have ended on the roof. And /his lord/ Eren wouldn't have been swallowed by this… abomination.

/Galahad/ Armin screams in pain and rage, gripping the hilt of his weapon. This beast has taken the life of /his lord/ Eren, so it's only fair he takes its life in turn. He jumps in the air, carefully avoiding the grabby hands of the titan.

"For all their size, these things are rather stupid," /Galahad/ Armin notes, "All the better. This won't take long."

It doesn't. Just not because of /Galahad's/ Armin's skill with a sword.

He strikes swiftly and his aim is deadly, had his opponent been a human, it would already be dead. But this beast is no man, and /Galahad/ Armin knows he has to cut out the nape of its neck. However, when he's about to deliver the finishing blow, the world explodes in a brilliant light. It promptly takes out majority of the titans wandering through Trost and /Galahad/ Armin (after blinking a few times to get rid of the black spots dancing in front of his eyes) hardly supresses a smile; Excalibur lost none of its power.

VI.

When /Lancelot/ Mikasa sees the golden light of Excalibur, she knows something has gone wrong in the worst way possible. /Her king/ Eren wouldn't have used his Sword unless there was no other choice, and certainly not after he forbad all of the knights to use their Noble Phantasms. Which means something bad has happened.

So Mikasa does the sensible thing – rushes towards the source of the light. She arrives in time to see /her king/ Eren falling towards the ground and suddenly she is falling too, because there is no more gas in her maneuver-gear.

"Shi-!" She hisses as she tumbles towards the ground, until somebody gripes her arm and yanks her upwards. When she looks up, she recognizes Connie.

"Mikasa, are you all right!?" he sounds worried and a little desperate, as he pulls her on a half-destroyed roof.

"Yeah." She nods and turns around to inspect what has become of her king. For a moment all she can thing about is that she failed yet again, but then she sees /Galahad/ Armin hanging mid-air, with Eren in his arms. She lets out a relieved sigh and Galahad suddenly looks up, straight into her eyes. She inclines her head and he nods back in return. Just like that, she knows her king is safe, for now. Galahad and Lancelot had never quite gotten along, there was just too much bad blood between them. Mikasa and Armin, that is a different story all together. At least when it comes to their king, there is no space for old quarrels.

She turns her attention back at Connie, who is talking about the mysterious light and if she knows anything about it.

"No," she lies, but doesn't feel too bad about it, "I didn't arrive in time to see what exactly happened."

"Ah, Okay, makes sense," he hums and then waves at Galahad Armin, "Hey man, did you see what happened here!? And why's Eren unconscious!?"

He is quite loud, Connie. But it's okay for now, there are no monsters to hear him.

"Eh, I'm not sure," Armin replies as he lands on the rooftop, "there wasn't much to see, the light was just too bright. But it did wipe out most of the titans, so there's that."

He slowly lowers Eren to the roof tiles and Mikasa frowns. Her kings is unconscious, but the Sword of Promised Victory has yet to disappear. It's very faint and barely visible, the wind hiding the blade calm but definitely there.

This may pose a problem, especially if someone tries to forcefully remove the sword. She exchanges glances with /Galahad/ Armin. Fortunately, Connie has yet to notice the sword. Unfortunately, there's no way they can hide it completely.

The answer to this problem comes in the form of a small man with black hair, wearing a green cape over the standard military uniform. Mikasa has to remind herself that no, murder does not solve most of the problems, including this one.

VII.

When the small man lands on the roof, Armin knows it means trouble. He has no way of making his king's sword disappear (as it already should have, what is going on?) and he's not as naïve as to think the man will not notice.

The man notices within a few heartbeats. Trust Scouts to be perceptive.

"What he hell happened here, kids? We were just leaving for an expedition when we saw that damned light – What. Is. This?"

The Scout's voice is irritated, until he sees the translucent sword in Eren's hand. Then it is baffled AND irritated.

"A sword," Mikasa deadpans and Armin has to hold a snicker. Mikasa's poker-face is a thing to behold. Connie looks like he wants to cry and laugh at the same time and Armin understands that perfectly. It's quite proper reaction to such a situation.

"Of course it is," growls the small soldier. He clearly wants to say something more… colourful but decides not to. "I'm asking why the damned sword," he looks at Mikasa pointedly; she just stares back, "is glowing."

And it really is glowing, faintly, but undeniably.

"I fail to see how that's any of your business," Mikasa says, face unreadable. But Armin knows her well enough to know her patience is wearing thin. Their king is wounded (most likely) and unconscious (certainly), they are all on edge. And the small soldier is not helping.

"It's very much my business, since this," he gestures towards Excalibur, "is most likely the source of that light. Which wiped out majority of the titans in this area. And I want answers. You seem to have them, so. Talk. Now." The last part is growled, the soldier is clearly in bad mood.

"No," Mikasa flat out refuses. Probably not the best course of action, but nobody would believe the truth, so… There's not much they can do.

"No? Well, fine," the soldier comes closer to Eren and Armin tenses, "I'll just get the answers myself." He makes a move towards the sword, probably intending to grab it.

At this point, Armin has to physically restrain Mikasa. She looks ready to commit a murder, and that will not help their king at all.

The small soldier touches the translucent blade; the moment he does so, the blade disintegrates, leaving behind small freckles of golden dust. The soldier freezes and for a moment just stares at the place where the sword was. Connie is doing the same, looking utterly baffled.

"What the…" the soldier trails off and shakes his head in disbelief. Then he seems to regain his composure, because he orders another member of the Scouting legion that's suddenly there: "Take these brats away and bind the unconscious one. We'll continue the questioning at the base." Then he takes to the air and is gone.

He lets go of /Mikasa/ Lancelot. Thankfully, nobody died. Killing members of the only capable unit of the military forces won't do any good. He's just glad Gawain's not here. It would have been much worse. It will be, once Gawain hears what happened.

Good grief.

This world is not ready for them at all.


End file.
